Within the field of computing, many scenarios involve an archive comprising a set of one or more objects (e.g., files, media objects, database records, or email messages), possibly including other features, such as compression, encryption, random accessibility, revision tracking, and a hierarchical organization. In many such scenarios, the archive includes security verifiers that may be used to verify the contents of the archive. As a first example, a hashing algorithm may enable a hashcode to be calculated as a value derived from the contents of the stored data at the time that the archive was created. At a later time, the contents of the archive may be tested for consistency by using the same hashing algorithm to calculate a current hashcode value for the archive and comparing the two values. Because any change in the data comprising the archive results in a different calculated hashcode, a failed comparison indicates a change somewhere in the data, while a successful comparison indicates a consistent object. In some cases, a change in the object may occur in an arbitrary manner (e.g., data corruption, damage to the physical medium containing the object, or an error in the reading or writing of the object), but in other cases, the change may be caused by a second user who has maliciously changed the object. Therefore, it may be desirable to design the archive to render changes unavoidably detectable. For example, the hashcode may be cryptographically signed with a self-verifying signature, and the signature may be added to the archive. A user who receives the archive may verify the integrity of the signature (e.g., against a public key corresponding to a private key with which the archive was signed), the integrity of the hashcode signature, and the correspondence of the hashcode with the contents of the archive. The failure of any of these verifications or the absence of these authentication items may indicate an intended or inadvertent alteration of the archive, while a success of these verifications may verify the integrity of the archive with a high degree of confidence.